Spark plug gap

[maxparplus]

"38 Flathead -what's the recommended gap?
The ones I pulled out were gapped to .22 thousands and were burning OK.
I gapped the new Motorcraft to .30 thousands? Feedback?

Thanks,
Max

 

[Barlea]

Back when coins were silver, a quarter would do for plugs and a thin dime for points. ..B.

 

[Mark Slight]

Give this a try it took me 20 seconds. The gap is going to get wider with use not smaller.

http://www.vanpeltsales.com/FH_web/flathead_tuneup32-48_221-239.htm

Mark

 

[fordscript]

Ford book says, 'twenty five one thousandths of an inch, no more, no less'.

 

[Walt Dupont--Me.]

Well, the book says .025 for most of the 6 volt systems. When the car has been converted to 12 volt I usually set them 30-32, If you set them to wide and have a hot coil it's hard on the dist cap. Walt

 

[BUBBAS IGNITION]

I agree with Walt.
Plug gap is very misunderstood when discussing engines etc.
Spark plug gap is set by the manufacture of the engine based on compression,air fuel mixtures and rpm of operation.
Lean air fuel typically require larger gaps, however wider gaps use more kvs of
Secondary voltage.
Higher kvs cause increased wear on ignition parts etc.

 

[cmbrucew]

If your flathead compression is low, due to worn rings, and tends to foul the plugs, try a wider gap.

Bruce

Works good
Lasts long time